The deep structure of a sea-floor hydrothermal deposit

Zierenberg, Robert A.; Fouquet, Yves; Miller, D.J.; Bahr, Jean M.; Baker, Paul A.; Bjerkgård, T.; Brunner, Charlotte A; Duckworth, Rowena C.; Gable, Robert S.; Gieskes, Joris M.; Goodfellow, Wayne D.; Gröschel-Becker, Henrike M.; Guèrin, G.; Ishibashi, Jun Ichiro; Iturrino, G. J.; James, Rachael H.; Lackschewitz, Klas; Márquez, Leopoldo; Nehlig, Pierre; Peter, Jan M.; Rigsby, Catherine A.; Schultheiss, Peter; Shanks, Wayne C.; Simoneit, Bernd R.T.; Summit, Melanie; Teagle, D. A. H.; Urbat, M.; Zuffa, Gian Gaspare

doi:10.1038/33126

Cited by 110 publications

(53 citation statements)

References 8 publications

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“…Sedimentation was contemporaneous with active extension and volcanism, creating an uppermost basement that consists of a basaltic-sill/sediment complex ( DAVIS and VILLINGER, 1992). Past hydrothermal activity has formed two seafloor massive sulfide deposits: the Bent Hill massive sulfide deposit (BHMS), which is estimated to contain over 8 million tons of ore, and the smaller, younger ODP Mound massive sulfide deposit (ZIERENBERG et al, 1998).…”

Section: Geologic Settingmentioning

confidence: 99%

Geochemistry of low-molecular weight hydrocarbons in hydrothermal fluids from Middle Valley, northern Juan de Fuca Ridge

Cruse

Seewald

2006

Geochimica et Cosmochimica Acta

108

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Hydrothermal vent fluids from Middle Valley, a sediment-covered mid-ocean ridge on the northern Juan de Fuca Ridge, were sampled in July, 2000. Eight different vents with exit temperatures of 186 to 281°C were sampled from two areas of venting: the Dead Dog and ODP Mound fields. Fluids from the Dead Dog field are characterized by higher concentrations of ΣNH 3 and organic compounds (C 1 -C 4 alkanes, ethene, propene, benzene and toluene) compared with fluids from the ODP Mound field. The ODP Mound fluids, however, are characterized by higher C 1 /(C 2 +C 3 ) and benzene:toluene ratios than those from the Dead Dog field. The aqueous organic compounds in these fluids have been derived from both bacterial processes (methanogenesis in low-temperature regions during recharge) as well as from thermogenic processes in higher-temperature portions of the subsurface reaction zone. As the sediments undergo hydrothermal alteration, carbon dioxide and hydrocarbons are released to solution as organic matter degrades via a stepwise oxidation process. Compositional and isotopic differences in the aqueous hydrocarbons indicate that maximum subsurface temperatures at the ODP Mound are greater than those at the Dead Dog field. Maximum subsurface temperatures were calculated assuming that thermodynamic equilibrium is attained between alkenes and alkanes, benzene and toluene, and carbon dioxide and methane. The calculated temperatures for alkene-alkane equilibrium are consistent with differences in the dissolved Cl concentrations in fluids from the two fields, and indicate that subsurface temperatures at the ODP Mound are hotter than those at the Dead Dog field. Temperatures calculated assuming benzene-toluene equilibrium and carbon dioxide-methane equilibrium are similar to observed exit temperatures, and do not record the hottest subsurface conditions. The difference in subsurface temperatures estimated using organic geochemical thermometers reflects subsurface cooling processes via mixing of a hot, low-salinity vapor with a cooler, seawater salinity fluid. Because of the disparate temperature dependence of alkene-alkane and benzene-toluene equilibria, the mixed fluid records both the high and low temperature equilibrium conditions. These calculations indicate that vapor-rich fluids are presently being formed in the crust beneath the ODP Mound, yet do not reach the surface due to mixing with the lower-temperature fluids.2

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Section: Geologic Settingmentioning

confidence: 99%

Geochemistry of low-molecular weight hydrocarbons in hydrothermal fluids from Middle Valley, northern Juan de Fuca Ridge

Cruse

Seewald

2006

Geochimica et Cosmochimica Acta

108

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“…The Bent Hill Massive Sulfide (BHMS) deposit is a very large, mature deposit with a 94 m thick massive sulfide zone, interpreted to have formed at the seafloor, overlying a substantial (ϳ100 m thick) sulfide feeder zone Zierenberg et al, 1998). Leg 169 made two transects in the region of the Bent Hill massive sulfide mound, one north-south (Hole 1035F) and one east-west (Holes 1035D, G) ( Fig.…”

Section: Geologic Settingmentioning

confidence: 99%

“…Bent Hill is stratigraphically less complex than ODP Mound, having a single set of massive sulfide and associated feeder zones, as opposed to the three sets within the ODP Mound (Fig. 1b) Zierenberg et al, 1998).…”

Section: Geologic Settingmentioning

confidence: 99%

“…In addition, temporal and spatial observations of the chemistry of vent fluids at active hydrothermal systems such as TAG reveal the critical role of temperature and redox conditions on metal mobility and alteration of primary metal sulfides. Similarly, there is evidence of fault control of upflow at Middle Valley (Ames et al, 1993;Goodfellow and Franklin, 1993), but hydrothermal fluids pass through ϳ500 m of clastic sediments before venting at the seafloor, which strongly affects hydrothermal processes due to reaction with sediments and mixing with fluids circulating in sediments (Stein et al, 1998;Zierenberg et al, 1998). Thus, the chemistry of massive sulfides at Middle Valley provides critical information on the extent to which fluid/sediment reactions and processes such as mixing with seawater influence sulfide deposition and composition.…”

Section: Introductionmentioning

confidence: 96%

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Massive sulfide deposition and trace element remobilization in the Middle Valley sediment-hosted hydrothermal system, northern Juan de Fuca Rdge

Houghton

Shanks

Seyfried

2004

Geochimica et Cosmochimica Acta

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“…The increase in Cu whole rock content (up to 42 µg/g) in the ophicarbonate could be related to hydrothermal activity on the ocean floor related to volcanism (Zierenberg et al, 1998), or hosted by Fig. 8.…”

mentioning

confidence: 99%

Emplacement of ultramafic rocks into the continental crust monitored by light and other trace elements: An example from the Geisspfad body (Swiss-Italian Alps)

et al. 2008

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In order to evaluate the influence of continental crustal rocks on trace element budgets of serpentinized peridotites incorporated into the continental crust, we have analyzed the chemical composition of whole rock samples and minerals of the Geisspfad ultramafic complex (Swiss-Italian Alps). This complex represents a relict oceanic succession composed of serpentinites, ophicarbonates and metabasic rocks, emplaced into crustal gneisses during Alpine collision. Following peak metamorphic amphibolite facies conditions, fluid flow modified some of the trace element contents of ophicarbonates and deformed serpentinites close to the contact with country rocks. The fluid originated from the surrounding continental crustal rocks as documented by the increase of Pb in the serpentinites, and by the strongly negative ∂D values (−112‰) of some ultramafic rocks close to the contact with surrounding gneisses. Little or no modification of the fluid mobile elements Li, B or U was observed in the serpentinite. In-situ analysis of light elements of serpentinite minerals indicate redistribution of light elements coupled to changes of mineral modes towards the outer 100-150 m of the massif. In the centre of the massif, Li is preferentially concentrated in olivine, while Be and B are hosted by tremolite. In contrast, at the outer rim of the massif, Li and Be are preferentially incorporated into diopside, and B into antigorite. This redistribution of light elements among the different minerals is visible in the serpentinite, at a maximum distance of~100-150 m from the ophicarbonate-metabasite contact. Our results show that interaction of ultramafic rocks and crust-derived fluids can be easily detected by studies of Pb and ∂D in whole rocks. We argue that small ultramafic bodies potentially record an emplacement-related trace element signature, and that crustal light element values in ultramafic rocks are not necessarily derived from a subducting slab.

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The deep structure of a sea-floor hydrothermal deposit

Cited by 110 publications

References 8 publications

Geochemistry of low-molecular weight hydrocarbons in hydrothermal fluids from Middle Valley, northern Juan de Fuca Ridge

Geochemistry of low-molecular weight hydrocarbons in hydrothermal fluids from Middle Valley, northern Juan de Fuca Ridge

Massive sulfide deposition and trace element remobilization in the Middle Valley sediment-hosted hydrothermal system, northern Juan de Fuca Rdge

Emplacement of ultramafic rocks into the continental crust monitored by light and other trace elements: An example from the Geisspfad body (Swiss-Italian Alps)

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